Method for correcting a service quality index of a risk indicator of a pressure vessel

Abstract

The method for modifying the service quality index of the risk index of the pressure vessel comprises the following steps: S1: establishing the risk assessment score of the pressure vessel, recorded in table 1; S2: establishing a judgment matrix according to the data in table 1, and determining the weight of the index; S3: dividing each index into evaluation grades, i.e. evaluation set V={C1, C2, K, C k}; dividing the evaluation grades into four, percentizing the evaluation grade, establishing a grade vector S={A, B, C, D}; S4: dividing the evaluation index grade, establishing table 2, and obtaining the membership degree of the bottom layer index according to table 2; according to the membership degree of the bottom layer, the membership degree of the top layer is constituted; according to the membership degree of the top layer in S4 and the grade vector in S3, the service quality index is calculated. The method considers the internal material type factor and the process condition factor, and can make the service quality index calculation more accurate.

Description

Technical Field

[0001] This invention pertains to pressure vessel risk assessment methods, specifically a method for correcting the service quality index, a risk indicator for pressure vessels. Background Technology

[0002] A pressure vessel is a closed device that holds gas or liquid and withstands a certain pressure.

[0003] The "Regulations on Supervision and Management of Special Equipment Users' Implementation of Primary Responsibility for Safety Use" stipulate that special equipment users must establish a dynamic management mechanism for safety risk prevention and control. However, the current risk assessment index system for pressure vessels only considers four aspects: personnel factors, equipment factors, environmental factors, and management factors. It lacks consideration of two aspects: the types of materials inside the pressure vessel and the pressure vessel's process factors.

[0004] This results in an incomplete evaluation scope and inaccurate service quality scores. Summary of the Invention

[0005] The present invention provides a method for correcting the service quality index, a risk indicator for pressure vessels, which takes into account the types of materials inside the pressure vessel and the process factors of the pressure vessel, making the calculated service quality score more accurate.

[0006] To achieve the above objectives, the present invention provides a method for correcting the service quality index, a risk indicator of pressure vessels, comprising the following steps:

[0007] S1: Establish risk assessment scores for pressure vessels and record them in Table 1;

[0008] Table 1. Corrected Index System for Risk Assessment of In-Service Pressure Vessels

[0009]

[0010]

[0011]

[0012]

[0013] S2: Based on the data in Table 1, establish a judgment matrix and determine the weights of the indicators;

[0014] S3: Divide each indicator into comment levels, i.e., comment set V = {C1, C2, K, C...} k The evaluation level is divided into 4 levels, and the evaluation level is converted into a percentage value to establish a level vector S = {A, B, C, D}.

[0015] S4: Divide the evaluation index levels and establish Table 2. Calculate the membership degree of the lowest-level index based on Table 2. Based on the membership degree of the lowest-level index, construct the membership degree of the highest-level index.

[0016] Table 2 Classification of Evaluation Indicator Levels

[0017]

[0018] a m(k-1) a mk These are the upper and lower limits for classifying indicator values;

[0019] S5: Calculate the service quality index based on the membership degree of the outermost layer in S4 and the rank vector in S3.

[0020] Further, step S2 includes:

[0021] S21: Calculate the product M of all elements in each row. k ,Right now:

[0022]

[0023] S22: Calculate M k nth root

[0024]

[0025] S23: Normalization process yields index weights

[0026]

[0027] S24: Find the largest eigenvalue

[0028]

[0029] S25: Consistency test, using the random consistency index C R The consistency check is performed using the following formula:

[0030]

[0031]

[0032] C R As a random consistency indicator, C is generally used. R A value ≤0.1 indicates that the consistency requirement of the judgment matrix is ​​met. If it is not met, the judgment matrix should be modified until the consistency requirement is met.

[0033] Furthermore, in S4, assume the value of the j-th indicator is t.

[0034]

[0035] d jc =min(|b jc -a jc |,|b j(c+1) -a jc |) (8)c=1, 2,...,k; j=1, 2,...,m;

[0036] The attribute measure function μ of the indicator jc (t) is as follows

[0037]

[0038] The membership matrix B of the secondary indicators corresponding to the primary indicators is calculated using equation (9). i By B i The membership matrix B that constitutes the primary indicators;

[0039] B i =W i u i , i = 1, 2, 3, 4 (10)

[0040] A = WB (11).

[0041] Further, in step S5, the service quality index is calculated:

[0042] Q = AS (12)

[0043] In the formula: Q is the service quality index; A is the membership vector of the service quality of the pressure vessel; S is the rating vector.

[0044] Furthermore, in step S3, in S = {A, B, C, D}, A is 0-25%, B is 26-50%, C is 51-75%, and D is 76-100%.

[0045] Beneficial effects:

[0046] This method takes into account the types of materials inside the pressure vessel and the pressure vessel process factors in Table 1, making the final calculated service quality score more accurate. Attached Figure Description

[0047] Figure 1 This is the flowchart of this method. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] A method for correcting the service quality index, a risk indicator for pressure vessels, includes the following steps:

[0050] S1: Establish risk assessment scores for pressure vessels and record them in Table 1;

[0051] Table 1. Corrected Index System for Risk Assessment of In-Service Pressure Vessels

[0052]

[0053]

[0054]

[0055]

[0056] The scores mentioned above are mainly determined by expert scoring and standard evaluation.

[0057] S2: Establish a judgment matrix and determine the weights of the indicators.

[0058] Based on Table 1 above, establish the judgment matrix A. n×n The importance of each element at each level relative to the elements above and below is expressed in matrix form. A scale of 1-5 is used to represent the importance between indicators, and the judgment matrix of indicators is obtained by comparing each indicator pairwise.

[0059] At the same time, the root method is used to find A. n×n The weights of each index are calculated using the largest eigenvalue. The specific sub-steps are as follows.

[0060] (I) Calculate the product M of all elements in each row. k ,Right now:

[0061]

[0062] For example: the score for personnel factor L1 is P; the scores for L11-L110 are N1-N10 respectively, and the sum of N1-N10 is P, then M k =N1*……N11.

[0063] (II) Calculate M k nth root

[0064]

[0065] (III) Normalization process to obtain index weights

[0066]

[0067] (IV) Finding the largest eigenvalue

[0068]

[0069] (V) Consistency test, using the random consistency index C R The consistency check is performed using the following formula:

[0070]

[0071]

[0072] In the formula: C R As a random consistency indicator, C is generally used. R A value ≤0.1 indicates that the consistency requirement of the judgment matrix is ​​met. If it is not met, the judgment matrix should be modified until the consistency requirement is met.

[0073] S3: Experts evaluate and assign rating levels to each indicator, i.e., the rating set V = {C1, C2, K, C...} k The evaluation comments can be divided into four levels, and the percentage values ​​of each level can be used to obtain a level vector S = {A, B, C, D}. For example, A is 0-25%, B is 26-50%, C is 51-75%, and D is 76-100%.

[0074] S4: Calculate the membership degree of the lowest-level indicator. Based on the actual requirements, classify the evaluation levels into C1, C2, K, and C6. k As shown in Table 2, a m(k-1) a mk These are the upper and lower limits for classifying indicator values.

[0075] Table 2 Classification of Evaluation Indicator Levels

[0076]

[0077] Assuming the value of the j-th indicator is t, the indicator attribute measure function μ needs to be obtained from Table 2. jc (t), in Table 2, assume that a is satisfied. j0 <a ji <K<a jk ,make

[0078]

[0079] djc =min(|b jc -a jc |,|b j(c+1) -a jc |) (8)

[0080] In the formula: c = 1, 2, ..., k; j = 1, 2, ..., m.

[0081] The attribute measure function μ of the indicator jc (t) is as follows

[0082]

[0083] The membership matrix (μ) of the secondary indicators corresponding to the primary indicators can be calculated through the above steps. jc The membership vector B of each primary indicator is obtained by multiplying the weights of the secondary indicators (obtained in S2) by the membership matrix of the secondary indicators (obtained in S4). i By B i Membership matrix B constituting the primary indicators

[0084] B i =W i u i , i = 1, 2, 3, 4 (10)

[0085] In the formula: W i This indicates the corresponding secondary indicator weight; u i This represents the corresponding second-level membership matrix. The second-level membership matrix is ​​the same as the aforementioned lowest-level membership matrix.

[0086] By multiplying the weights of each primary indicator (also calculated in S2) with the membership matrix B, the membership vector A of the pressure vessel service quality can be obtained.

[0087] A = WB (11)

[0088] In the formula: W represents the weight of the first-level indicator; B represents the membership matrix of the first-level indicator. The first-level membership matrix is ​​the aforementioned outermost membership matrix.

[0089] S5: Service Quality Index Calculation.

[0090] Q = AS (12)

[0091] In the formula: Q is the service quality index; A is the membership vector of the pressure vessel's service quality; S is the rating vector. The level of the service quality index determines whether the pressure vessel can meet the service requirements. The higher the service quality index, the safer the pressure vessel.

[0092] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for correcting the service quality index, a risk indicator for pressure vessels, characterized in that, Includes the following steps: S1: Establish risk assessment scores for pressure vessels and record them in Table 1; Table 1. Corrected Index System for Risk Assessment of In-Service Pressure Vessels ； ； ； ； ； ； S2: Based on the data in Table 1, establish a judgment matrix and determine the weights of the indicators; S3: Divide each indicator into comment levels, i.e., comment sets. The evaluation level is divided into four categories, and the evaluation level is converted into a percentage value to establish a level vector. ; S4: Divide the evaluation index levels and establish Table 2. Calculate the membership degree of the lowest-level index based on Table 2. Based on the membership degree of the lowest-level index, construct the membership degree of the highest-level index. Table 2 Classification of Evaluation Indicator Levels ； These are the upper and lower limits for classifying indicator values; S5: Calculate the service quality index based on the membership degree of the outermost layer in S4 and the rank vector in S3; Step S2 includes: S21: Calculate the product of the elements in each row. ,Right now: （1）； S22: Calculation nth root （2）； S23: Normalization process yields index weights （3）； S24: Find the largest eigenvalue （4）； S25: Consistency test, using the random consistency index C R The consistency check is performed using the following formula: （5）； （6）； As a random consistency indicator, If the consistency requirement of the judgment matrix is ​​met, it is assumed that the condition is met. If not, the judgment matrix should be modified until the consistency requirement is met.

2. The method for correcting the service quality index, a risk indicator of pressure vessels, according to claim 1, is characterized in that, In S4, assume the value of the j-th indicator is t. ； Attribute measurement function of the indicator as follows ； The membership matrix of the secondary indicators corresponding to the primary indicators is calculated using equation (9). ,Depend on Membership matrix constituting the primary indicators B ; 。 3. The method for correcting the service quality index, a risk indicator for pressure vessels, according to claim 1, is characterized in that... In step S5, the service quality index is calculated: ； In the formula: Q Service quality index; A This represents the membership vector of the service quality of the pressure vessel. S This is the rating vector.

4. The method for correcting the service quality index, a risk indicator of pressure vessels, according to claim 1, is characterized in that... In step S3, In the above, A is 0-25%, B is 26-50%, C is 51-75%, and D is 76-100%.

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